Underwater Ranging

The paper deals with underwater laser ranging system, its principle of operation and maximum depth capability. The sources of external noise and methods to improve signal-to-noise ratio are also discussed

Laser Range Sensors

This paper presents the design aspects of laser range finders and proximity sensors beingdeveloped at IRDE for different applications. The principle used in most of the laser rangefinders is pulse echo or time-of-flight measurement. Optical triangulation is used in proximitysensors while techniques like phase detection and interferometry are employed in instrumentsfor surveying and motion controllers where high accuracy is desired. Most of the laser rangefinders are designed for ranging non-cooperative targets

Critical Analysis of Background Subtraction Techniques on Real GPR Data

Ground penetrating radar (GPR) is used to detect the underground buried objects for civil as well as defence applications under varying conditions of soil moisture content. The capability of detection depends upon soil moisture, target characteristics and subsurface characteristics, which are mainly responsible for contaminating the GPR images with clutter. Researchers earlier have used averaging, mean, median, Eigen values, etc. for subtracting the background from GPR images. To analyse the background subtraction or clutter reduction problems, in this paper, we have experimentally reviewed background subtraction techniques with or without target conditions to enhance the target detection under variable soil moisture content. Indigenously developed GPR has been used to collect the data for different soil conditions and several background subtraction signal processing techniques were critically reviewed like, mean, median, singular value decomposition (SVD), principal component analysis (PCA), independent component analysis (ICA) and training methods. The signal to clutter ratio (SCR) measurement has been used for performance evaluation of each technique. The relative merits and demerits of each technique has also been analysed. The background subtraction techniques have been appliedto experimental GPR data and it is observed that in comparison of mean, SVD, median, ICA, PCA, the training method shows the highest SCR with buried target. Finally, this review helps to select the comparatively better background subtraction technique to enhance the detection capability in GPR

New observational method framework and application

© 2017 19th ICSMGE Secretariat. All rights reserved. This paper introduces the new holistic Observational Method (OM) framework described in Ciria C760 -the new revision to the Embedded Retaining Wall Design Guide. This new OM framework is described by four approaches and these are explained with reference to case histories. Maximum benefit is achieved by back analyzing case histories in similar ground conditions to derive the most probable soil parameters. These parameters can then be used in an ab initio design to maximize saving in the wall thickness, toe embedment, and propping forces. A contingency plan is based on conventional characteristic design parameters and this involves additional propping. The term ipso tempore is introduced to cover wall redesign after construction starts. This may be to achieve saving in propping where movements are smaller than predicted. Alternatively, additional propping or ground treatment may be required and this is consistent with Peck's 'best way out' approach.Ove Arup Lt

Fractal motor activity regulation and sex differences in preclinical Alzheimer\u27s disease pathology

Introduction: Degradation in fractal motor activity regulation (FMAR), a measure of multiscale self-similarity of motor control, occurs in aging and accelerates with clinical progression to Alzheimer\u27s disease (AD). Whether FMAR changes occur during the pre-symptomatic phase of the disease in women and men remains unknown. Methods: FMAR was assessed in cognitively normal participants (n = 178) who underwent 7 to 14 days of home actigraphy. Preclinical AD pathology was determined by amyloid imaging-Pittsburgh compound B (PiB) and cerebrospinal fluid (CSF) phosphorylated-tau181 (p-tau) to amyloid beta 42 (Aβ42) ratio. Results: Degradation in daytime FMAR was overall significantly associated with preclinical amyloid plaque pathology via PiB+ imaging (beta coefficient Discussion: Changes in daytime FMAR from actigraphy appear to be present in women early in preclinical AD. This may be a combination of earlier pathology changes in females reflected in daytime FMAR, and a relatively underpowered male group. Further studies are warranted to test FMAR as an early noncognitive physiological biomarker that precedes the onset of cognitive symptoms

A COMPETENT MAC SCHEME DESIGNED USING A UNIQUE DNA-BRNG KEY AND A NOVEL HASH ALGORITHM

The current communication sector demands security over anything else. Considering the confidential data transmission and involvement of technology in everyday payment modes, many schemes have been employed in order to achieve this goal. Authentication and integrity form the base of a secure system, and various research techniques have been employed for primarily prevention and secondarily detection of data modification. MAC serves the best purpose when it comes to retention of integrity, and its efficiency is increased on pairing it up with a secret key. In this paper, a new message authentication code (MAC) is proposed based on feature extraction of the user's DNA and Bernoulli Random Number Generator’s sequence used as key along with a novel hash algorithm. This scheme ensures integrity and the evaluation is done on the basis of NIST test suite for random numbers, which evaluates the outputs by calculating their P value which has to be greater than 0.01 and strict avalanche criteria. Further the performance of the proposed algorithm is analyzed by comparing it with other existing HMAC schemes available and evaluating its behavior towards various network attacks. The proposed scheme has strong security attributes since it involves the fusion of unique biological characteristics along with technical aspects thus making it applicable for data sensitive environments

Risk-Reducing Salpingo-Oophorectomy and the Use of Hormone Replacement Therapy Below the Age of Natural Menopause: Scientific Impact Paper No. 66

This paper deals with the use of hormone replacement therapy (HRT) after the removal of fallopian tubes and ovaries to prevent ovarian cancer in premenopausal high risk women. Some women have an alteration in their genetic code, which makes them more likely to develop ovarian cancer. Two well-known genes which can carry an alteration are the BRCA1 and BRCA2 genes. Examples of other genes associated with an increased risk of ovarian cancer include RAD51C, RAD51D, BRIP1, PALB2 and Lynch syndrome genes. Women with a strong family history of ovarian cancer and/or breast cancer, may also be at increased risk of developing ovarian cancer. Women at increased risk can choose to have an operation to remove the fallopian tubes and ovaries, which is the most effective way to prevent ovarian cancer. This is done after a woman has completed her family. However, removal of ovaries causes early menopause and leads to hot flushes, sweats, mood changes and bone thinning. It can also cause memory problems and increases the risk of heart disease. It may reduce libido or impair sexual function. Guidance on how to care for women following preventative surgery who are experiencing early menopause is needed. HRT is usually advisable for women up to 51 years of age (average age of menopause for women in the UK) who are undergoing early menopause and have not had breast cancer, to minimise the health risks linked to early menopause. For women with a womb, HRT should include estrogen coupled with progestogen to protect against thickening of the lining of the womb (called endometrial hyperplasia). For women without a womb, only estrogen is given. Research suggests that, unlike in older women, HRT for women in early menopause does not increase breast cancer risk, including in those who are BRCA1 and BRCA2 carriers and have preventative surgery. For women with a history of receptor-negative breast cancer, the gynaecologist will liaise with an oncology doctor on a case-by-case basis to help to decide if HRT is safe to use. Women with a history of estrogen receptor-positive breast cancer are not normally offered HRT. A range of other therapies can be used if a woman is unable to take HRT. These include behavioural therapy and non-hormonal medicines. However, these are less effective than HRT. Regular exercise, healthy lifestyle and avoiding symptom triggers are also advised. Whether to undergo surgery to reduce risk or not and its timing can be a complex decision-making process. Women need to be carefully counselled on the pros and cons of both preventative surgery and HRT use so they can make informed decisions and choices